Patent Literature 1 proposes a vehicle seat in which an inner-side slide rail fixed to a floor and an outer-side slide rail fixed to a wall portion allow a seat cushion to slide in a front-rear direction of a vehicle and in which the seat cushion is flipped up toward the wall portion of the vehicle to be folded. The outer-side slide rail includes: an outer-side lower rail having a first base wall portion fixed to the wall portion, a pair of side wall portions erected from two sides of the first base wall portion which are opposite to each other in the lateral direction, and a pair of first folded wall portions bent inward from the side wall portions in the lateral direction and folded toward base ends of the side wall portions; and an outer-side upper rail which is housed in the outer-side lower rail to be smoothly slidable with a bearing and which has a second base wall portion attached to a hinge mechanism installed in the seat cushion, and a vertical wall portion extending from the second base wall portion, and a pair of second folded wall portions bent outward from the vertical wall portion in the lateral direction and folded between the side wall portions and the first folded wall portions to movably support the bearing. The hinge mechanism has spring means, provided around a turning axis of this hinge mechanism, for biasing the seat cushion in a flipping-up direction. Moreover, a rolling member is provided which is pivotally supported on an attaching member fixed between the pair of second folded wall portions of the outer-side upper rail to be capable of turning about a vertical axis and which is disposed between the pair of first folded wall portions of the outer-side lower rail.